The so-called West Lothian question has been a well-worn term at Westminster for more than 30 years. But how did it get its name and what is its significance today?

What is the origin of the West Lothian Question?

The original question was posed by Labour MP Tam Dalyell, whose constituency used to be called West Lothian.

He asked how it could be right that a Scottish MP at Westminster could vote upon matters such as education affecting English seats - but that same MP could not vote on such matters affecting his own constituency because they would have been devolved to a Scottish Parliament.

Mr Dalyell's question was first posed on 14 November 1977 during a House of Commons debate over Scottish and Welsh devolution.

He illustrated his point by saying that is was absurd that the member for West Lothian was able to vote on matters affecting the English town of Blackburn, Lancashire, not Blackburn, West Lothian, which was in his own constituency.

After his explanation, Ulster Unionist MP Enoch Powell responded by saying: "Let us call it the West Lothian question."

Today, the question is more commonly assumed to challenge the fact that Scottish, Welsh and Northern Ireland members at Westminster can vote upon English matters, while MPs from England have no influence on Scottish, Welsh or Northern Ireland affairs which are devolved to their decision-making bodies.

Why have a commission into the question now?

This matter was part of the coalition agreement more than 12 months ago and lots of MPs had hoped the matter would have been dealt with before now.

It was expected that a commission into the issue would be set up because that was what was said at the time of the agreement, although there were strong suspicions that the matter could be kicked into the long grass.

However, the announcement came as West Worcestershire MP Harriett Baldwin's Private Members' Bill tackling the issue reached a crucial stage in the parliamentary process.

What did her bill aim to do?

In her Legislation (Territorial Extent) Bill 2010-11 she said that all bills should have clear indications on the front of them about which areas of the UK are affected and if they do not cover Scotland then Scottish MPs should not vote on them.

What has happened to the Private Members' Bill?

Constitutional Reform Minister Mark Harper had asked the Tory MP to withdraw her legislation, but she refused.

Ms Baldwin took her bill to the House of Commons on Friday, 9 September, for its third reading.

She began the debate by saying: "There are increasingly large numbers of legislation which come before this House that affect England only.

"If this House continues not to tackle that particular issue, it will become increasingly an issue our constituents find extremely distressing."

In the end her colleagues were not convinced by her proposal and the Private Members' Bill was rejected by 40 votes to 24, giving the government a majority of 16.

What will the commission do?

It will have a wide-ranging remit with the hope of answering all of the questions surrounding the issue.

What is the remit of the commission?

The make-up, exact remit and timetable of the commission is still at an early stage.

A written statement announcing the body said: "The government believes that the commission should be comprised of a small group of independent, non-partisan experts with constitutional, legal and parliamentary expertise."

The commission will consult the Speaker and political parties will be allowed to feed into the process.

The terms of reference for the commission will be made public in October.

What might the conclusions be?

There have been some resolutions suggested in the past, with the possibility of an English Grand Committee set up to consider English-only bills, another suggestion was that MPs would not be allowed to vote on bills that do not relate to them in the House of Commons.